A sanding and polishing device for large steel castings

Abstract

This invention relates to the field of casting surface treatment equipment technology, and discloses a large-scale sand-removing and grinding processing device for cast steel parts. The device includes a support base mechanism, a lifting mechanism, an outer cylinder, a main shaft, a drive assembly, a grinding assembly, a fluid stiffness-adjusting and central water control mechanism, and an anti-overcutting mechanical unloading mechanism. The support base mechanism includes a U-shaped positioner and a gantry frame spanning both sides above the U-shaped positioner. The lifting mechanism is mounted on the gantry frame and includes a Z-axis linear module with a vertically movable slide. The outer cylinder is vertically mounted on the slide. By setting a water guide sleeve and a T-shaped plunger at the center of the main shaft and grinding wheel, a fluid stiffness-adjusting and central water control mechanism is constructed. When the T-shaped plunger contacts the workpiece burr and is lifted, the water outlet window on its side wall is blocked by the inner wall of the water guide sleeve, cutting off the fluid discharge path inside the main shaft. The downward stiffness of the main shaft is adaptively adjusted according to the undulation of the processed surface.

Description

Technical Field

[0001] This invention relates to the field of casting surface treatment equipment technology, specifically a sand removal and grinding processing device for large cast steel parts. Background Technology

[0002] After casting and demolding, large cast steel parts typically have residual molding sand, flash, and burrs on their surface, requiring cleaning with grinding equipment. Current automated cleaning equipment often uses a gantry structure with a floating grinding spindle to process the casting surface to accommodate dimensional tolerances. However, in actual processing, when faced with thick burrs, the floating spindle is easily pushed away due to insufficient downward pressure rigidity, failing to provide sufficient cutting force to effectively remove the burrs. If the cutting force is increased by increasing the spindle's downward support rigidity, excessive rigidity when the grinding wheel cuts the burrs and contacts the casting base material can lead to over-cutting of the base material, damaging the dimensions and surface morphology of the casting.

[0003] To avoid over-cutting, some equipment uses distance sensors in conjunction with the CNC system for monitoring and spindle retraction control. In the dusty, cutting fluid-rich processing environment of a foundry, electronic sensors are prone to measurement errors due to contamination. Furthermore, the entire process—from sensor signal acquisition and CNC system command processing to the mechanical execution of spindle retraction—involves a time delay, making it difficult to achieve mechanical unloading and retraction at the instant the grinding wheel contacts the workpiece. In addition, existing heavy-duty grinding spindles, during operation, require internal transmission components and water-cooled sealing structures to simultaneously withstand transmission torque and axial impact forces. This complex stress state can easily lead to seal failure and wear of transmission components, making it difficult to maintain high-rigidity cutting while ensuring structural stability during rapid retraction. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a sand-removing and grinding processing device for large cast steel parts, which solves the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a large-scale casting steel part sand removal and grinding processing device, comprising a supporting base mechanism, a lifting mechanism, an outer cylinder, a main shaft, a drive assembly, a grinding assembly, a fluid stiffness variable and central water control mechanism, and an anti-overcutting mechanical unloading mechanism. The supporting base mechanism includes a U-shaped positioner and a gantry frame spanning both sides above the U-shaped positioner. The lifting mechanism is mounted on the gantry frame and includes a Z-axis linear module. The Z-axis linear module has a slide block that can move up and down. The outer cylinder is vertically mounted on the slide block. The upper side wall of the outer cylinder is provided with a water inlet. The main shaft is partially movably inserted into the inner cavity of the outer cylinder and has a central water channel penetrating its interior. The drive assembly is located outside the outer cylinder and provides rotational power. The grinding assembly is mounted on the bottom end of the main shaft extending from the outer cylinder and includes a grinding wheel with a horizontal bottom surface. The fluid stiffness variable and central water control mechanism is located inside the main shaft. The grinding wheel center includes a water guide sleeve installed at the center of the grinding wheel and a T-shaped plunger slidably inserted into the water guide sleeve. When the bottom end of the T-shaped plunger is pushed upward, it blocks the water flow from the spindle to the bottom end of the grinding wheel, thereby intercepting the water flow in the upper part of the inner cavity of the outer cylinder and forming a high-pressure water column that applies downward pressure. By physically displacing and cutting off the water path, the bearing rigidity of the spindle under downward pressure is improved. The anti-overcutting mechanical unloading mechanism is located outside the outer cylinder and the grinding wheel, including a movable sleeve. The outer cylinder has an annular frame at its bottom periphery, a trigger-type outer ring connected to the bottom of the annular frame, a connecting rod whose bottom end is connected to the top of the annular frame, and a pressure relief slide valve disposed on the outside of the side wall of the outer cylinder and cooperating with the top of the connecting rod. When the trigger-type outer ring is pushed upward, it drives the annular frame and the connecting rod to move upward. The connecting rod pushes open the pressure relief slide valve to discharge the water pressure in the outer cylinder, thereby eliminating the rigid downward pressure on the main bearing and obtaining a retraction stroke when approaching the workpiece base material.

[0006] Furthermore, to achieve dynamic and static decoupling between the transmission structure and the water pressure sealing components, an independently configured splined shaft is coaxially connected to the top of the main shaft. The central water channel of the main shaft extends upward through the interior of the splined shaft. The drive assembly includes a motor mounted on the outside of the outer cylinder via a mounting bracket. A splined sleeve is rotatably mounted in the middle section of the inner cavity of the outer cylinder. An auxiliary bearing is fitted on the outer periphery of the top and bottom ends of the splined sleeve. An annular groove is formed in the middle of the outer wall of the splined sleeve. A sprocket is installed in the annular groove and at the output end of the motor. The two sprockets are connected by a chain drive. A window is formed on the side wall of the outer cylinder for the chain to pass through. A shell covering the chain and the window is provided on the side wall of the outer cylinder. The splined shaft is slidably inserted into the inside of the splined sleeve and moves with the splined sleeve. The system rotates and slides up and down relative to the main shaft. A compression spring abuts between the bottom of the spline sleeve and the top of the main shaft. An isolation piston disc is slidably arranged above the spline shaft in the inner cavity of the outer cylinder. The water inlet is connected to a sealed chamber above the isolation piston disc. A thrust bearing is placed between the bottom surface of the isolation piston disc and the top end face of the spline shaft. A fixed opening is made at the center of the isolation piston disc and a downward-extending water guide pipe is installed. The water guide pipe passes downward through the center of the thrust bearing and the top of the spline shaft and is inserted into the center water channel. Through the cooperation of the isolation piston disc and the thrust bearing, the fluid pressure is converted into axial thrust applied to the rotating component, avoiding direct impact of high-pressure fluid on the rotating seal and improving the system's operational stability under heavy load conditions.

[0007] Furthermore, to adaptively adjust local water pressure and provide lubrication, the top of the water guide sleeve is inserted into the central water channel of the spindle. A water outlet groove is formed on the bottom end face of the water guide sleeve. The top diameter of the T-shaped plunger is larger than its bottom diameter to form an anti-detachment step. A water outlet window is formed on the side wall of the T-shaped plunger, connecting to the internal water flow. When the T-shaped plunger is in its lowest limit position, the water outlet window is connected to the water outlet groove. When the T-shaped plunger moves upward, the water outlet window is physically blocked by the inner wall of the water guide sleeve. In addition, a microporous channel extending to the bottom surface is formed inside the T-shaped plunger along its central axis. A cross-shaped pressure equalization groove communicating with the microporous channel is formed at the center of the bottom surface of the T-shaped plunger. This structure allows a small amount of fluid to flow out through the microporous channel when the main water channel is blocked, establishing a static pressure water film between the bottom surface of the T-shaped plunger and the workpiece surface, reducing rotational friction resistance.

[0008] Furthermore, to achieve rapid unloading of fluid pressure and simultaneous auxiliary cleaning, a drain tank is fixedly installed on the upper middle outer wall of the outer cylinder. The internal chamber of the outer cylinder is radially connected to the drain tank through a connecting hole. The pressure relief valve is vertically slidably installed inside the drain tank to control the opening and closing state of the connecting hole. A drain pipe extending downwards is led out from the lower side wall of the drain tank. The upper end of the connecting rod movably passes into the interior of the drain tank and is directly opposite the bottom end of the pressure relief valve. The portion of the pressure relief valve blocking the connecting hole forms a T-shaped sliding plate. Two L-shaped limiting plates are fixedly installed on the outer wall of the outer cylinder, inside the drain tank. The two L-shaped limiting plates are engaged with the pressure relief valve. The outer side of the T-shaped slide plate of the pressure relief valve is designed to limit the lateral displacement of the valve when subjected to water pressure impact. The bottom surface of the trigger-type outer ring is evenly inlaid with multiple balls along the circumferential direction. In the initial non-contact state, the bottom of the balls is lower than the bottom surface of the grinding wheel. A hollow annular flow channel is provided inside the trigger-type outer ring. The lower end of the drain pipe is connected to the hollow annular flow channel. A water outlet is provided between two adjacent balls on the bottom surface of the trigger-type outer ring. The hollow annular flow channel is connected to the cavity where the balls are installed. When the pressure is released, the fluid discharged directly flushes the balls and is discharged outward through the water outlet to clean the waste in the processing area.

[0009] Furthermore, to ensure the reliability of component movement and the effectiveness of workpiece clamping, multiple limiting blocks are fixedly installed on the outer periphery of the bottom end of the outer cylinder. The trigger-type outer ring is supported by the multiple limiting blocks. Two limiting grooves are symmetrically opened on the outer wall of the bottom end of the spindle. Two limiting blocks that cooperate with the limiting grooves are symmetrically arranged on the inner wall of the bottom of the outer cylinder to limit the downward sliding stroke of the spindle. A rotating frame is provided in the rotation center area of ​​the U-shaped positioner. A clamping assembly for laterally clamping and fixing the cast steel part is assembled on the inner side of the rotating frame. The rotating frame is a hollow structure so that the top and bottom surfaces of the cast steel part are exposed in the hole area to avoid operational interference between the clamping structure and the grinding assembly.

[0010] This invention provides a sand-removing and grinding device for large cast steel parts. It has the following beneficial effects: 1. This invention constructs a fluid variable stiffness and central water control mechanism by setting a water guide sleeve and a T-shaped plunger at the center of the spindle and the grinding wheel. When the T-shaped plunger contacts the burr of the workpiece and is lifted, the water outlet window on its side wall is blocked by the inner wall of the water guide sleeve, cutting off the fluid discharge path inside the spindle. This physical displacement intercepts the fluid in the upper part of the inner cavity of the outer cylinder and forms a high-pressure water column, which transmits rigid downward pressure downward, causing the grinding wheel to generate cutting force on the burr. This structure uses mechanical displacement to realize the opening and closing of the water channel and adaptively adjusts the downward pressure stiffness of the spindle according to the undulation state of the machining surface. 2. This invention utilizes a trigger-type outer ring, annular frame, connecting rod, and pressure relief slide valve on the side wall of the outer cylinder to form an anti-overcutting mechanical unloading mechanism. When grinding approaches the surface of the cast steel base material, the ball bearing at the bottom of the trigger-type outer ring contacts the base material before the grinding wheel and is lifted up. The thrust pushes open the external pressure relief slide valve through the annular frame and connecting rod, and the high-pressure fluid inside the outer cylinder is discharged into the drainage tank for pressure relief. The rigid downward pressure on the top of the spindle is eliminated, and the spindle obtains an upward retraction stroke, avoiding excessive cutting damage to the workpiece base material by the grinding components. 3. The drive assembly and water control system of the present invention adopt a dynamic-static decoupling structure. By isolating the piston disc, thrust bearing and spline shaft below, the static high-pressure water chamber at the top of the outer cylinder is isolated from the high-speed rotating main shaft below. The external motor drives the spline sleeve through the side sprocket, which drives the spline shaft to rotate synchronously and allows it to slide up and down. This design avoids the dynamic seal failure problem caused by the high-pressure fluid directly acting on the high-speed rotating seal. It separates the fluid thrust and rotational torque, and improves the operating stability of the device under heavy load and high pressure conditions. Attached Figure Description

[0011] Figure 1 This is a perspective view of the present invention; Figure 2 This is a front perspective view of the outer cylinder of the present invention; Figure 3 This is a bottom perspective view of the outer cylinder of the present invention; Figure 4 A schematic diagram illustrating the internal structure of the outer cylinder of this invention; Figure 5 for Figure 4 Enlarged view of point A in the middle; Figure 6 An exploded view is provided to highlight the internal structure of the outer cylinder of this invention; Figure 7 A schematic diagram highlighting the internal structure of the main shaft of this invention; Figure 8 To highlight the T-shaped plunger installation position diagram of the present invention; Figure 9 for Figure 8 Enlarged view of point B in the middle; Figure 10 This is a diagram showing the water flow discharge trend inside the outer cylinder of the present invention; Figure 11 This is a diagram showing the water flow trend during the sand-clearing process according to the present invention.

[0012] The components include: 1. Gantry frame; 2. Z-axis linear module; 3. Outer cylinder; 4. U-shaped positioner; 5. Water inlet; 6. Main shaft; 7. Limiting groove; 8. Splined shaft; 9. Splined sleeve; 10. Sprocket; 11. Compression spring; 12. Auxiliary bearing; 13. Thrust bearing; 14. Isolation piston disc; 15. Water guide pipe; 16. Motor; 17. Drainage tank; 18. L-shaped limiting plate; 19. Pressure relief slide valve; 20. Drainage pipe; 21. Limiting support block; 22. Ring frame; 23. Trigger-type outer ring; 24. Connecting rod; 25. Limiting hanging block; 26. Water outlet hole; 27. Ball bearing; 28. Grinding wheel; 29. ​​Water guide sleeve; 30. Water outlet groove; 31. T-shaped plunger; 32. Water outlet window; 33. Cross pressure equalization groove. Detailed Implementation

[0013] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] Please see the appendix Figure 1 - Appendix Figure 3 This invention provides a large casting steel part cleaning and grinding processing device, including a support base mechanism, a lifting mechanism, an outer cylinder 3, a main shaft 6, a drive assembly, a grinding assembly, a fluid stiffness and central water control mechanism, and an anti-overcutting mechanical unloading mechanism. The support base mechanism includes a U-shaped positioner 4 and a gantry frame 1 spanning both sides above the U-shaped positioner 4. The rotation center area of ​​the U-shaped positioner 4 is provided with a through hollow rotating frame or a non-hollow worktable. The inner side of the hollow rotating frame is equipped with a clamping assembly for laterally clamping and fixing the casting steel part, so that the top and bottom surfaces of the casting steel part are exposed in the hole area. The lifting mechanism is installed on the gantry frame 1 and includes a Z-axis linear module 2. The Z-axis linear module 2 has a slide that can move up and down. The outer cylinder 3 is vertically installed on the slide. The main shaft 6 is partially movably inserted into the inner cavity of the outer cylinder 3. The grinding assembly includes a grinding wheel 28 installed at the bottom end of the main shaft 6 with a horizontal bottom surface. See attached document Figure 4 and Figure 6The drive assembly is located outside the outer cylinder 3, including a motor 16 mounted on the outside of the outer cylinder 3 via a mounting bracket. A spline sleeve 9 is rotatably mounted in the middle section of the inner cavity of the outer cylinder 3. An auxiliary bearing 12 is respectively fitted on the outer periphery of the top and bottom of the spline sleeve 9. An annular groove is opened in the middle of the outer wall of the spline sleeve 9, and a sprocket 10 is installed in the annular groove. A corresponding sprocket 10 is installed at the output end of the motor 16. The two sprockets 10 are connected by a chain drive. A window for the chain to pass through is opened on the side wall of the outer cylinder 3. A shell covering the side wall of the outer cylinder 3 is provided outside the chain and the window to maintain the sealing of the inside of the outer cylinder 3. An independently set spline shaft 8 is coaxially connected to the top of the main shaft 6. The spline shaft 8 is slidably inserted into the spline sleeve 9, so that the spline shaft 8 can rotate synchronously with the spline sleeve 9, and at the same time has the freedom to slide up and down relative to the spline sleeve 9. A compression spring 11 abuts between the bottom of the spline sleeve 9 and the top of the main shaft 6. See attached document Figure 6 and Figure 7 The upper side wall of the outer cylinder 3 is provided with a water inlet 5. An isolation piston disc 14 is slidably arranged above the spline shaft 8 in the inner cavity of the outer cylinder 3. The water inlet 5 is connected to the sealed chamber above the isolation piston disc 14. A thrust bearing 13 is provided between the bottom surface of the isolation piston disc 14 and the top end face of the spline shaft 8. A hole is fixed in the center of the isolation piston disc 14 and a downwardly extending water guide pipe 15 is installed. The main shaft 6 has a central water channel that runs through its interior. The central water channel runs upward through the interior of the spline shaft 8. The water guide pipe 15 passes downward through the center of the thrust bearing 13 and the top of the spline shaft 8 and is inserted into the central water channel. When working, the isolation piston disc 14 bears the fluid pressure above. The water pressure is transmitted to the rotating spline shaft 8 and the main shaft 6 below through the thrust bearing 13. The water flows into the central water channel of the rotating main shaft 6 through the non-rotating water guide pipe 15. See attached document Figure 8 , Figure 9 and Figure 11 The fluid variable stiffness and central water control mechanism includes a water guide sleeve 29 installed at the center of the grinding wheel 28 and a T-shaped plunger 31 slidably inserted in the water guide sleeve 29. The top of the water guide sleeve 29 is inserted into the central water channel of the spindle 6. A water outlet groove 30 is opened on the bottom end face of the water guide sleeve 29. The top diameter of the T-shaped plunger 31 is larger than its bottom diameter to form an anti-detachment step. A water outlet window 32 is opened on the side wall of the T-shaped plunger 31 to connect with the water flow inside. When the T-shaped plunger 31 is at the lowest limit position, the water outlet window 32 is connected to the water outlet groove 30. When the bottom end of the T-shaped plunger 31 contacts the workpiece and is pushed upward, the T-shaped plunger 31 moves upward, and the water outlet window 32 is physically blocked by the inner wall of the water guide sleeve 29. After the water flow is cut off, the water flow will be intercepted in the upper part of the inner cavity of the outer cylinder 3 and a high-pressure water column will be formed to apply downward pressure. See attached document Figure 9The T-shaped plunger 31 has a micro-hole channel extending to the bottom surface along its central axis. A cross-shaped pressure equalization groove 33 communicating with the micro-hole channel is opened at the center of the bottom surface of the T-shaped plunger 31. When the T-shaped plunger 31 blocks the main water passage, the water flows into the cross-shaped pressure equalization groove 33 through the micro-hole channel, forming a static pressure water film between the bottom surface of the plunger and the workpiece. See attached document Figure 4 , Figure 5 and Figure 10 The anti-overcutting mechanical unloading mechanism includes a drainage box 17 fixedly installed on the upper outer wall of the outer cylinder 3. The internal chamber of the outer cylinder 3 is radially connected to the drainage box 17 through a connecting hole. The pressure relief valve 19 is vertically slidably installed inside the drainage box 17 to control the opening and closing state of the connecting hole. The part of the pressure relief valve 19 that blocks the connecting hole forms a T-shaped slide. Two L-shaped limiting plates 18 are fixedly installed on the outer wall of the outer cylinder 3 and inside the drainage box 17. The two L-shaped limiting plates 18 are relatively fastened to the outside of the T-shaped slide of the pressure relief valve 19 to limit the lateral displacement of the pressure relief valve 19. A downwardly extending drainage pipe 20 is led out from the lower position of the side wall of the drainage box 17. The upper end of the connecting rod 24 is movably inserted into the interior of the drainage box 17 and is directly opposite the bottom end of the pressure relief valve 19. See attached document Figure 2 , Figure 3 and Figure 4 The outer cylinder 3 is fixedly fitted with an annular frame 22 at the bottom outer periphery, and multiple limiting blocks 25 are fixedly installed at the bottom outer periphery of the outer cylinder 3. The trigger-type outer ring 23 is supported by multiple limiting blocks 25, so that the bottom of the trigger-type outer ring 23 protrudes a fixed distance from the bottom of the grinding wheel 28. The bottom end of the connecting rod 24 is connected to the top of the annular frame 22. Two limiting grooves 7 are symmetrically opened on the outer wall of the bottom end of the main shaft 6. Two limiting blocks 21 that cooperate with the limiting grooves 7 are symmetrically arranged on the inner wall of the bottom of the outer cylinder 3 to limit the downward limit of the main shaft 6. See attached document Figure 8 The bottom surface of the trigger-type outer ring 23 is evenly inlaid with multiple balls 27 along the circumferential direction. In the initial non-contact state, the bottom of the balls 27 is horizontally lower than the bottom surface of the grinding wheel 28. The trigger-type outer ring 23 has a hollow annular flow channel inside. The lower end of the drain pipe 20 is connected to the hollow annular flow channel. The bottom surface of the trigger-type outer ring 23 has a water outlet hole 26 between two adjacent balls 27. The hollow annular flow channel is connected to the cavity where the balls 27 are installed. During grinding, when the ball 27 at the bottom of the trigger outer ring 23 contacts the workpiece and is lifted upward, the trigger outer ring 23 drives the ring frame 22 and connecting rod 24 to move upward. The connecting rod 24 pushes open the pressure relief valve 19, and the water in the outer cylinder 3 enters the drain tank 17 and flows into the hollow annular flow channel of the trigger outer ring 23 through the drain pipe 20. The fluid enters the cavity to directly clean the ball 27 and is discharged to the outside through the water outlet 26. At this time, the pressure in the outer cylinder 3 is discharged, and the fluid pressure of the spindle 6 is released, avoiding excessive cutting of the surface of the cast steel base material by the grinding assembly.

[0015] Working principle: Before operation, the cast steel parts to be processed are clamped in the hollow rotating frame of the U-shaped positioner 4. The U-shaped positioner 4 adjusts the processing angle of the cast steel parts. The gantry 1 provides cross-support for the overall structure. The external water source injects fluid into the sealed chamber at the top of the outer cylinder 3 through the water inlet 5. The fluid pressure acts on the top surface of the isolation piston disc 14. The thrust is transmitted to the spline shaft 8 through the thrust bearing 13, which pushes the main shaft 6 to move downward. The limiting groove 7 on the side wall of the main shaft 6 contacts the limiting support block 21 at the bottom of the outer cylinder 3, limiting the downward movement limit of the main shaft 6. The motor 16 starts, and the rotational power is transmitted to the sprocket 10 through the chain, which drives the spline sleeve 9 to rotate. The spline sleeve 9 is supported by the auxiliary bearings 12 at both ends in the outer cylinder 3 to maintain rotational stability. The spline shaft 8 rotates synchronously with the spline sleeve 9 and drives the main shaft 6 and the grinding wheel 28 to rotate. The fluid is introduced from the sealed chamber into the central water channel of the main shaft 6 through the water guide pipe 15 and flows downward. The Z-axis linear module 2 is activated, and the outer cylinder 3, with its ram, descends to approach the cast steel part. The T-type plunger 31 is at its lowest limit position, and fluid flows out from the water outlet 30. When the bottom end of the T-type plunger 31 contacts the protruding burrs on the surface of the workpiece, as the outer cylinder 3 continues to descend, the surface of the workpiece forces the T-type plunger 31 to slide upward relative to the water guide sleeve 29. The side wall of the T-type plunger 31 and the inner wall of the water guide sleeve 29 undergo relative displacement. The water outlet window 32 is blocked by the inner wall of the water guide sleeve 29, and the fluid discharge path in the central water channel of the main shaft 6 is cut off. Fluid continues to enter the inner cavity of the outer cylinder 3, forming a high-pressure water column above the isolation piston disc 14. The high-pressure water column provides a downward rigid pressure to the isolation piston disc 14, the spline shaft 8, and the main shaft 6, causing the grinding wheel 28 to apply cutting pressure to the protruding burrs. With the water outlet window 32 blocked, the high-pressure fluid in the central water channel flows into the cross pressure equalization groove 33 on the bottom surface through the microporous channel inside the T-shaped plunger 31. The fluid overflows between the bottom surface of the T-shaped plunger 31 and the workpiece surface, forming a fluid-bearing water film between the contact surfaces, reducing the friction and wear between the T-shaped plunger 31 and the workpiece surface when it rotates with the spindle 6. As the grinding wheel 28 removes burrs and approaches the surface of the cast steel base material downwards, the ball 27 at the bottom of the trigger outer ring 23 contacts the cast steel base material before the bottom surface of the grinding wheel 28. The surface of the workpiece base material pushes the trigger outer ring 23 upwards, and the trigger outer ring 23 disengages from the contact support of the limiting block 25. The trigger outer ring 23 pushes the upper ring frame 22 to move upwards, and the ring frame 22 pushes the connecting rod 24 to move upwards simultaneously. The upper end of the connecting rod 24 pushes the pressure relief slide valve 19 upwards inside the drain tank 17. The two L-shaped limiting plates 18 engage with each other on their outer sides during the upward movement of the pressure relief slide valve 19, limiting the lateral displacement of the pressure relief slide valve 19. The T-shaped slide of the pressure relief valve 19 disengages from the connecting hole, and the high-pressure fluid in the inner cavity of the outer cylinder 3 is discharged into the drain tank 17 through the connecting hole. The fluid in the sealed chamber is depressurized and released, the rigid downward pressure on the top of the spindle 6 is eliminated, and the spindle 6 has the freedom to move upward under the action of the compression spring 11. The grinding wheel 28 stops applying strong cutting pressure to the workpiece base material. The fluid discharged into the drain tank 17 flows into the hollow annular flow channel of the trigger outer ring 23 along the drain pipe 20. The fluid enters the cavity where the ball bearings 27 are installed to physically clean the ball bearings 27, and then is discharged outward through the water outlet 26 to clean the cutting waste remaining in the machining area.

Claims

1. A sand-removing and grinding processing device for large cast steel parts, characterized in that, include: The supporting base structure includes a U-shaped positioner (4) and a gantry (1) spanning both sides above the U-shaped positioner (4). The lifting mechanism, installed on the gantry (1), includes a Z-axis linear module (2), which has a slide block that can move up and down; The outer cylinder (3) is vertically installed on the slide block, and the upper side wall of the outer cylinder (3) is provided with a water inlet (5). The main shaft (6) is partially movably inserted into the inner cavity of the outer cylinder (3), and the main shaft (6) has a central water channel that penetrates its interior; A drive assembly, located outside the outer cylinder (3), is used to provide rotational power; A grinding assembly is installed at the bottom end of the spindle (6) extending from the outer cylinder (3), including a grinding wheel (28) with a horizontal bottom surface. The fluid variable stiffness and central water control mechanism is set inside the main shaft (6) and the center of the grinding wheel (28), including a water guide sleeve (29) installed in the center of the grinding wheel (28) and a T-shaped plunger (31) slidably inserted in the water guide sleeve (29). When the bottom end of the T-shaped plunger (31) is pushed upward, it blocks the water flow from the main shaft (6) to the bottom end of the grinding wheel (28), and is used to intercept the water flow in the upper part of the inner cavity of the outer cylinder (3) and form a high-pressure water column that applies downward pressure. The anti-overcutting mechanical unloading mechanism is located outside the outer cylinder (3) and the grinding wheel (28). It includes an annular frame (22) movably sleeved on the outer periphery of the bottom end of the outer cylinder (3), a trigger-type outer ring (23) connected to the bottom of the annular frame (22), a connecting rod (24) whose bottom end is connected to the top of the annular frame (22), and a pressure relief slide valve (19) located outside the side wall of the outer cylinder (3) and cooperating with the top end of the connecting rod (24). When the trigger-type outer ring (23) is pushed upward, it drives the annular frame (22) and the connecting rod (24) to move upward, and pushes open the pressure relief slide valve (19) through the connecting rod (24) to discharge the water pressure in the outer cylinder (3).

2. The sand-removing and grinding device for large cast steel parts according to claim 1, characterized in that, The top of the main shaft (6) is coaxially connected to an independently configured spline shaft (8). The central water channel of the main shaft (6) extends upward through the interior of the spline shaft (8). The drive assembly includes a motor (16) mounted on the outside of the outer cylinder (3) via a mounting bracket. A spline sleeve (9) is rotatably mounted in the middle section of the inner cavity of the outer cylinder (3). An auxiliary bearing (12) is respectively fitted on the outer periphery of the top end and the outer periphery of the bottom end of the spline sleeve (9). An annular groove is formed in the middle of the outer wall of the spline sleeve (9). Both the output end of the motor (16) and the output end of the motor (16) are equipped with sprockets (10). The two sprockets (10) are connected by a chain drive. The outer cylinder (3) has a window on its side wall for the chain to pass through. The chain and the window are covered by a shell covering the side wall of the outer cylinder (3). The spline shaft (8) is slidably inserted into the spline sleeve (9), rotates synchronously with the spline sleeve (9) and slides up and down relative to it. A compression spring (11) abuts between the bottom of the spline sleeve (9) and the top of the main shaft (6).

3. The sand-removing and grinding device for large cast steel parts according to claim 2, characterized in that, An isolation piston disc (14) is slidably disposed above the spline shaft (8) in the inner cavity of the outer cylinder (3). The water inlet (5) is connected to the sealed chamber above the isolation piston disc (14). A thrust bearing (13) is provided between the bottom surface of the isolation piston disc (14) and the top end face of the spline shaft (8). A fixed opening is provided at the center of the isolation piston disc (14) and a downwardly extending water guide pipe (15) is installed. The water guide pipe (15) passes downward through the center of the thrust bearing (13) and the top of the spline shaft (8) and is inserted into the center water channel.

4. The sand-removing and grinding device for large cast steel parts according to claim 1, characterized in that, The top end of the water guide sleeve (29) is inserted into the central water channel of the main shaft (6). A water outlet groove (30) is provided on the bottom end face of the water guide sleeve (29). The top diameter of the T-shaped plunger (31) is larger than its bottom diameter to form an anti-detachment step. A water outlet window (32) is provided on the side wall of the T-shaped plunger (31) to connect with the water flow inside. When the T-shaped plunger (31) is in the lowest position, the water outlet window (32) is connected to the water outlet groove (30). When the T-shaped plunger (31) moves upward, the water outlet window (32) is physically blocked by the inner wall of the water guide sleeve (29).

5. The sand-removing and grinding device for large cast steel parts according to claim 4, characterized in that, The interior of the T-shaped plunger (31) is provided with a microporous channel extending to the bottom surface along its central axis, and a cross-shaped pressure equalization groove (33) communicating with the microporous channel is provided at the center of the bottom surface of the T-shaped plunger (31).

6. The sand-removing and grinding device for large cast steel parts according to claim 1, characterized in that, A drain box (17) is fixedly installed on the upper middle outer wall of the outer cylinder (3). The internal chamber of the outer cylinder (3) is radially connected to the drain box (17) through a connecting hole. The pressure relief valve (19) is vertically slidably installed inside the drain box (17) to control the opening and closing state of the connecting hole. A drain pipe (20) extending downwards is led out from the lower side wall of the drain box (17). The upper end of the connecting rod (24) is movably inserted into the interior of the drain box (17) and is directly opposite the bottom end of the pressure relief valve (19).

7. The sand-removing and grinding device for large cast steel parts according to claim 6, characterized in that, The portion of the pressure relief valve (19) that blocks the connecting hole forms a T-shaped slide. Two L-shaped limiting plates (18) are fixedly installed on the outer wall of the outer cylinder (3) and inside the drain tank (17). The two L-shaped limiting plates (18) are engaged with each other on the outside of the T-shaped slide of the pressure relief valve (19) to limit the lateral displacement of the pressure relief valve (19).

8. The sand-removing and grinding device for large cast steel parts according to claim 6, characterized in that, The bottom surface of the trigger-type outer ring (23) is evenly inlaid with multiple balls (27) along the circumferential direction. In the initial non-contact state, the bottom of the ball (27) is at a lower horizontal height than the bottom surface of the grinding wheel (28). The trigger-type outer ring (23) has a hollow annular flow channel inside. The lower end of the drain pipe (20) is connected to the hollow annular flow channel. The bottom surface of the trigger-type outer ring (23) has a water outlet hole (26) between two adjacent balls (27), and the hollow annular flow channel is connected to the cavity where the balls (27) are installed.

9. The sand-removing and grinding device for large cast steel parts according to claim 1, characterized in that, Multiple limiting blocks (25) are fixedly provided on the outer periphery of the bottom end of the outer cylinder (3). The trigger-type outer ring (23) is supported by the multiple limiting blocks (25). Two limiting grooves (7) are symmetrically opened on the outer side wall of the bottom end of the main shaft (6). Two limiting blocks (21) that cooperate with the limiting grooves (7) are symmetrically provided on the inner bottom wall of the outer cylinder (3) to limit the downward sliding stroke of the main shaft (6).

10. A sand-removing and grinding device for large cast steel parts according to claim 1, characterized in that, The U-shaped positioner (4) has a rotating frame in its rotation center area. The inner side of the rotating frame is equipped with a clamping assembly for laterally clamping and fixing the cast steel part. The rotating frame can be a hollow structure, so that the top and bottom surfaces of the cast steel part are exposed in the hole area.

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